commons-net.jar Source Code

commons-net.jar is the bytecode of Apache Commons Net library, which implements the client side of many basic Internet protocols.

Apache Commons Net Source Code files are provided in the binary packge (commons-net-3.8.0-bin.zip). You can download it at Apache Commons Net Website.

The source code of commons-net-3.8.0.jar is provided below:

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org/apache/commons/net/ftp/FTPListParseEngine.java

/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.commons.net.ftp;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.List;
import java.util.ListIterator;

import org.apache.commons.net.util.Charsets;


/**
 * This class handles the entire process of parsing a listing of
 * file entries from the server.
 * <p>
 * This object defines a two-part parsing mechanism.
 * <p>
 * The first part is comprised of reading the raw input into an internal
 * list of strings.  Every item in this list corresponds to an actual
 * file.  All extraneous matter emitted by the server will have been
 * removed by the end of this phase.  This is accomplished in conjunction
 * with the FTPFileEntryParser associated with this engine, by calling
 * its methods <code>readNextEntry()</code> - which handles the issue of
 * what delimits one entry from another, usually but not always a line
 * feed and <code>preParse()</code> - which handles removal of
 * extraneous matter such as the preliminary lines of a listing, removal
 * of duplicates on versioning systems, etc.
 * <p>
 * The second part is composed of the actual parsing, again in conjunction
 * with the particular parser used by this engine.  This is controlled
 * by an iterator over the internal list of strings.  This may be done
 * either in block mode, by calling the <code>getNext()</code> and
 * <code>getPrevious()</code> methods to provide "paged" output of less
 * than the whole list at one time, or by calling the
 * <code>getFiles()</code> method to return the entire list.
 * <p>
 * Examples:
 * <p>
 * Paged access:
 * <pre>
 *    FTPClient f=FTPClient();
 *    f.connect(server);
 *    f.login(username, password);
 *    FTPListParseEngine engine = f.initiateListParsing(directory);
 *
 *    while (engine.hasNext()) {
 *       FTPFile[] files = engine.getNext(25);  // "page size" you want
 *       //do whatever you want with these files, display them, etc.
 *       //expensive FTPFile objects not created until needed.
 *    }
 * </pre>
 * <p>
 * For unpaged access, simply use FTPClient.listFiles().  That method
 * uses this class transparently.
 */
public class FTPListParseEngine {
    private List<String> entries = new LinkedList<>();
    private ListIterator<String> internalIterator = entries.listIterator();

    private final FTPFileEntryParser parser;
    // Should invalid files (parse failures) be allowed?
    private final boolean saveUnparseableEntries;

    /**
     * An empty immutable {@code FTPFile} array.
     */
    private static final FTPFile[] EMPTY_FTP_FILE_ARRAY = new FTPFile[0];

    public FTPListParseEngine(final FTPFileEntryParser parser) {
        this(parser, null);
    }

    /**
     * Intended for use by FTPClient only
     * @since 3.4
     */
    FTPListParseEngine(final FTPFileEntryParser parser, final FTPClientConfig configuration) {
        this.parser = parser;
        if (configuration != null) {
            this.saveUnparseableEntries = configuration.getUnparseableEntries();
        } else {
            this.saveUnparseableEntries = false;
        }
    }

    /**
     * Reads (and closes) the initial reading and preparsing of the list returned by the server. After this method has
     * completed, this object will contain a list of unparsed entries (Strings) each referring to a unique file on the
     * server.
     *
     * @param inputStream input stream provided by the server socket.
     * @param charsetName the encoding to be used for reading the stream
     *
     * @throws IOException thrown on any failure to read from the sever.
     */
    public void readServerList(final InputStream inputStream, final String charsetName) throws IOException {
        this.entries = new LinkedList<>();
        read(inputStream, charsetName);
        this.parser.preParse(this.entries);
        resetIterator();
    }

    /**
     * Internal method for reading (and closing) the input into the <code>entries</code> list. After this method has
     * completed, <code>entries</code> will contain a collection of entries (as defined by
     * <code>FTPFileEntryParser.readNextEntry()</code>), but this may contain various non-entry preliminary lines from
     * the server output, duplicates, and other data that will not be part of the final listing.
     *
     * @param inputStream The socket stream on which the input will be read.
     * @param charsetName The encoding to use.
     *
     * @throws IOException thrown on any failure to read the stream
     */
    private void read(final InputStream inputStream, final String charsetName) throws IOException {
        try (final BufferedReader reader = new BufferedReader(
            new InputStreamReader(inputStream, Charsets.toCharset(charsetName)))) {

            String line = this.parser.readNextEntry(reader);

            while (line != null) {
                this.entries.add(line);
                line = this.parser.readNextEntry(reader);
            }
        }
    }

    /**
     * Returns an array of at most <code>quantityRequested</code> FTPFile
     * objects starting at this object's internal iterator's current position.
     * If fewer than <code>quantityRequested</code> such
     * elements are available, the returned array will have a length equal
     * to the number of entries at and after after the current position.
     * If no such entries are found, this array will have a length of 0.
     *
     * After this method is called this object's internal iterator is advanced
     * by a number of positions equal to the size of the array returned.
     *
     * @param quantityRequested
     * the maximum number of entries we want to get.
     *
     * @return an array of at most <code>quantityRequested</code> FTPFile
     * objects starting at the current position of this iterator within its
     * list and at least the number of elements which  exist in the list at
     * and after its current position.
     * <p><b>
     * NOTE:</b> This array may contain null members if any of the
     * individual file listings failed to parse.  The caller should
     * check each entry for null before referencing it.
     */
    public FTPFile[] getNext(final int quantityRequested) {
        final List<FTPFile> tmpResults = new LinkedList<>();
        int count = quantityRequested;
        while (count > 0 && this.internalIterator.hasNext()) {
            final String entry = this.internalIterator.next();
            FTPFile temp = this.parser.parseFTPEntry(entry);
            if (temp == null && saveUnparseableEntries) {
                temp = new FTPFile(entry);
            }
            tmpResults.add(temp);
            count--;
        }
        return tmpResults.toArray(EMPTY_FTP_FILE_ARRAY);

    }

    /**
     * Returns an array of at most <code>quantityRequested</code> FTPFile
     * objects starting at this object's internal iterator's current position,
     * and working back toward the beginning.
     *
     * If fewer than <code>quantityRequested</code> such
     * elements are available, the returned array will have a length equal
     * to the number of entries at and after after the current position.
     * If no such entries are found, this array will have a length of 0.
     *
     * After this method is called this object's internal iterator is moved
     * back by a number of positions equal to the size of the array returned.
     *
     * @param quantityRequested
     * the maximum number of entries we want to get.
     *
     * @return an array of at most <code>quantityRequested</code> FTPFile
     * objects starting at the current position of this iterator within its
     * list and at least the number of elements which  exist in the list at
     * and after its current position.  This array will be in the same order
     * as the underlying list (not reversed).
     * <p><b>
     * NOTE:</b> This array may contain null members if any of the
     * individual file listings failed to parse.  The caller should
     * check each entry for null before referencing it.
     */
    public FTPFile[] getPrevious(final int quantityRequested) {
        final List<FTPFile> tmpResults = new LinkedList<>();
        int count = quantityRequested;
        while (count > 0 && this.internalIterator.hasPrevious()) {
            final String entry = this.internalIterator.previous();
            FTPFile temp = this.parser.parseFTPEntry(entry);
            if (temp == null && saveUnparseableEntries) {
                temp = new FTPFile(entry);
            }
            tmpResults.add(0,temp);
            count--;
        }
        return tmpResults.toArray(EMPTY_FTP_FILE_ARRAY);
    }

    /**
     * Returns an array of FTPFile objects containing the whole list of
     * files returned by the server as read by this object's parser.
     *
     * @return an array of FTPFile objects containing the whole list of
     *         files returned by the server as read by this object's parser.
     * None of the entries will be null
     * @throws IOException - not ever thrown, may be removed in a later release
     */
    public FTPFile[] getFiles()
    throws IOException // TODO remove; not actually thrown
    {
        return getFiles(FTPFileFilters.NON_NULL);
    }

    /**
     * Returns an array of FTPFile objects containing the whole list of
     * files returned by the server as read by this object's parser.
     * The files are filtered before being added to the array.
     *
     * @param filter FTPFileFilter, must not be <code>null</code>.
     *
     * @return an array of FTPFile objects containing the whole list of
     *         files returned by the server as read by this object's parser.
     * <p><b>
     * NOTE:</b> This array may contain null members if any of the
     * individual file listings failed to parse.  The caller should
     * check each entry for null before referencing it, or use the
     * a filter such as {@link FTPFileFilters#NON_NULL} which does not
     * allow null entries.
     * @since 2.2
     * @throws IOException - not ever thrown, may be removed in a later release
     */
    public FTPFile[] getFiles(final FTPFileFilter filter)
    throws IOException // TODO remove; not actually thrown
    {
        final List<FTPFile> tmpResults = new ArrayList<>();
        final Iterator<String> iter = this.entries.iterator();
        while (iter.hasNext()) {
            final String entry = iter.next();
            FTPFile temp = this.parser.parseFTPEntry(entry);
            if (temp == null && saveUnparseableEntries) {
                temp = new FTPFile(entry);
            }
            if (filter.accept(temp)) {
                tmpResults.add(temp);
            }
        }
        return tmpResults.toArray(EMPTY_FTP_FILE_ARRAY);

    }

    /**
     * convenience method to allow clients to know whether this object's
     * internal iterator's current position is at the end of the list.
     *
     * @return true if internal iterator is not at end of list, false
     * otherwise.
     */
    public boolean hasNext() {
        return internalIterator.hasNext();
    }

    /**
     * convenience method to allow clients to know whether this object's
     * internal iterator's current position is at the beginning of the list.
     *
     * @return true if internal iterator is not at beginning of list, false
     * otherwise.
     */
    public boolean hasPrevious() {
        return internalIterator.hasPrevious();
    }

    /**
     * resets this object's internal iterator to the beginning of the list.
     */
    public void resetIterator() {
        this.internalIterator = this.entries.listIterator();
    }

    // DEPRECATED METHODS - for API compatibility only - DO NOT USE

    /**
     * Do not use.
     * @param inputStream the stream from which to read
     * @throws IOException on error
     * @deprecated use {@link #readServerList(InputStream, String)} instead
    */
    @Deprecated
    public void readServerList(final InputStream inputStream) throws IOException {
        readServerList(inputStream, null);
    }

}

org/apache/commons/net/ftp/FTPListParseEngine.java

 

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